1. Field of the Invention
This invention is related to apparatus for utilizing controlled air flow for classifying the material delivered off the dischrage of a rotary disc screen conveyor.
2. Description of the Prior Art
It is known that material fed onto a rotary screen conveyor may consist of a highly varied assortment of waste, trash and the like which has a varied specific gravity. The rotary screen usually employs a system of rotating discs which define openings between discs so that the heavier fractions in the trash or waste are able to migrate to the openings for collection under the screen disc while the rotation of the discs conveys the remainder of material. However, the remainder of the waste and trash that continues to be delivered off the end of the screen is a residual assortment of fractions that are especially difficult to efficiently sort out and economically classify. There is the problem with those residual fractions as to what can be recycled and what can be used as a fuel for example. An example of a rotary disc screen conveyor is found in my prior U.S. Pat. No. 4,658,964 of Apr. 21, 1987. Other prior patents of interest for classifying material are U.S. Pat. No. 4,337,900 of July 6, l982 and U.S. Pat. No. 4,339,085 of July 13, 1982.